Process of obtaining potassium sulfate.



BENJAMIN A. PEACOCK, or PHILADELPHIA, PENNSY -LVANIA, AssiGNon To HAsLuP &

rEAcooK, me, on NEW YORK, N. Y., ncon-ronn'rron OF NEW YORK.

PROCESS on OBTAINING POTASSIUM S LFA E. 1

No Drawing.

To all whom it may concern:

Be it known that I, BENJAMIN A. PEA- oocK, a citizen of the United States, residing at Philadelphia, in the countyof Philadelphia'and State of Pennsylvania, have invented certain new and useful Improvements in Processes of Obtaining Potassium Sulfate; andI' do hereby declarethe follow ing to be a full, clear, and exact description I the claims.

In order that the invention may be clearly understood it is said :It has been heretofore proposed to treat minerals of the kind above mentioned with boiling acids, such as sulfuric, for example, but as said minerals usually contain relatively large proportions of aluminum oxid, and also may contain iron oxids, which combine with the acid employed to extract the combined potassium, it is found that a very large percentage of said acid is expended in producing sulfates of aluminum and iron, which have very little commercial value, and that therefore the cost of the potassium sulfate produced is very greatly increased. These facts may be illustrated by an example. A ton of ordinary run of the mine glauconite will contain acid consuming oxids and will require acid as follows Ferric oxid, 295 lbs.,

B. sulfuric acid.

Total acid required- 1,684 pounds acid.

Of the total acid, 1684: pounds, required to decompose a ton of glauconite it will thus Specification of Letters Patent.

Application filed February 8, 1818. Serial No. 216,078.

be seen that only 168 pounds, Off say 10% is utilized in producing the desiredgpotassium sulfate, the remaining 90%, of acid is thus practically lost in producing products of little or nocommercial value.

I ha'veldiscovered, on theother hand, that if the comparatively inexpensive sulfates 'of aluminum and iron, ferric and ;ferrous,;;b.e

mixed in the first instance with a naturally occurring hydrous potassium bearing mineral such as glauconite, and'in such. quantities as to supply only slightly more sulfuric anhydrid than is necessary to form a sulfate with all the potassium present, and if the mixture be heated well above say 100 0., for some hours, say twenty-four or forty-eight, or less, according to the temperature employed, the mineral is decomposed to the extent that the potassium present is converted into a sulfate and may be extracted with water. That is to say, ifonly aluminum oxids are present in the mineral I mix with the latter aluminum sulfate, but if both aluminum and iron oxids are present inthe mineral, I add the sulfates of both aluminum and iron. 1

I have further found that the sulfates of iron and aluminum need not be added to the mineral, but may be formed therein and then decomposed. Thatis to say, by restricting the amount of acid required to. that slightly in excess of whatis necessary to convert all the potassium present into a sulfate, I find that equivalent amounts of iron and aluminum sulfates will be first formed with very little if any potassium sulthese said sulfates are decomposed-with the a formation of potassium sulfate which is then leached out with water.

Of course, the mineral is preferably em- I ployed in a finely divided condition, or ground to say 60 mesh, and impure or relatively cheap acids are preferred to lessen j the costs of the process.

It is obvious that those skilled in the art may vary the details of the process without departing from the spirit of the invention, and therefore, I do not wish to be limited to the above disclosure except as may be required by the claims.

WVhat I claim is 1. The process of extracting combined potassium from a hydrous mineral containing the same, such as glauconite, which consists in providing a mixture containing said mineral and aluminum sulfate, the latter being present in a quantity only slightly in excess of that required to supply sufficient sulfuric anhydrid to combine With all the potassiumpresent; heating said mixture to a temperature sufficient to decompose said sulfate in the presence of said potassium to form potassium sulfate; and extracting the latter from the'mass, substantially as described.

2. The process of extracting potassium sulfate from glauconite Which consists in copiesotthia patent may be obtained for providing a finely divided mixture containingglauconite and aluminum sulfate, the

latter being present in a 1 quantity only slightly in excess of that required to'supply sufficient sulfuric an'hydrid to combine With all the potassium present; heating said mixture to a temperature above 100 C. for a time suflicient to form the desired potassium sulfate; and extracting the latter with Water, substantially as described.

In testimony whereof I affix my'signature in presence of two Witnesses. r

BENJAMIN A. PEAQOCK;

Witnesses OWEN CRAVEN, \VM. E. BLAIR.

five cents each, by addressing the Commissioner of Patents Waahington, D. 0. I 

